Process of producing artificial staple fibers resembling wool



PROCESS OF PRODUCING ARTIFICIAL STAPLE FIBERS RESEBIBLING WOOL PaulEsselmann, Wolfen, Kreis Bittcrfeld, and Fritz Davidshiifer, Dessau,Anhalt, Germany, assignors, by mesne assignments, to Walther H.Duisberg, New York, N. Y.

No Drawing. Application July 24, 1937, Serial No. 155,576. In GermanyAugust 26, 1936 Claims. (01. 18-54) Our present invention relates to aprocess of a temperature of 103 C. The fibers are then spinningartificial fibers from viscose solutions. washed, after-treated anddried. The fibers thus It is an object of the present invention toproobtained have a wool-like appearance and, alvide a process by whichartificial staple fibers though they have been spun from cellulose, aresembling wool are produced. 5 fine matt luster. Particularly strikingis its good Further objects will be apparent from the decurliness withvery finely curved crimps. Under tailed specification followinghereafter. the microscope the fiber exhibits numerous According to thisinvention artificial fibers crater-like openings which impart to it ahigh having an appreciably better resemblance to wool capacity ofadhesion. The fibers have a round are obtained by spinning a morestrongly ripened cross-section. viscose directly into an alcoholicprecipitating What we claim is: bath, for example into methanol, ethylalcohol or 1. A process of producing artificial staple fibers the like,and then subjecting the freshly coaguresembling wool, which comprisesspinning vislated fibers to a final decomposition. The most cose in aprecipitating bath containing more than satisfactory results in respectof curliness and 70 per cent of an alcohol of comparatively low power ofadhesion are obtained if the fibers are boiling point and subsequentlydecomposing the cut into staple lengths before the decomposition,freshly coagulated xanthate threads by subjectsince the fibers can thenshrink more completely. ing said threads to the action of a mediumhaving Obviously, however, the fiber can also be suba temperature offrom about 90 to about 150 C. jected to decomposition and finished inits endless 2. A process of producing artificial staple fibers uncutstate. The final fixing 0f the fibers ll). the resembling W001, whichcomprises spinning V15- form of regenerated cellulose can be broughtcose in a precipitating bath containing more than 9 in Venous Ways forexample treatment 70 per cent of an alcohol of comparatively low withhot air, whereby at the same time the alcob 011m g point, cutting thefreshly coagulated hol associated with the fiber is evaporated and canbe recovered, or by treatment with a hot acid Xanthate threads mtoStaples and Subsequently or a h t; San; Solution decomposing saidthreads by subjecting them to The finished, after-treated d dried fiberthe action of a medium having a temperature of have the appearance ofwool in respect of curlifrom about 90 to about 150 C.

ness and superficial structure. Their physical 3. A process of producingartificial staple fibers p p t e can be regulated y S ching themresembling wool, which comprises spinning visduring spinning, forexample after they have left cose in a. precipitating bath containingmore than the first precipitating bath or during the first 70 per centof an alcohol of comparatively low decomposition of the xanthate. Theprocess may boiling point, cutting the freshly coagulated be conductedwith the usual spinning nozzles xanthate threads into staples andsubsequently having orifices of 0.07-0.09 mm. diameter or withdecomposing said threads by subjecting them to nozzles having orifices0f 0- diameter the action of a hot acid solution having a temnd re; inthe l ter e the fi r y be perature of from about 90 to about 120 C.simultaneously drawn out in a stretch-spinning 4. A process of producingartificial staple fibers funnel. 4o resembling wool, which comp-risesspinning vis- The fibers may be desulfurized during coagucose in aprecipitating bath containing more than lation or during the finaldecomposition. 70 per cent of an alcohol of comparatively low Instead ofmethanol or ethanol any monoor boiling point, cutting the freshlycoagulated p yvalent alcohols or mixtures of alcohols may xanthatethreads into staples and subsequently be used. There may be usedmixtures of alcohol decomposing said threads by subjecting them to andwater, but the water content of these mixthe action of a hot inorganicsalt solution having tu s s u d not exceed 30 per cent. a temperature offrom about 90 to about 130 c.

The temperature of the final decomposition 5. Aprocess of producingartificial staple fibers may be from about 90 to 150 C., in some casesresembling wool, which comprises spinning visev her. cose containing 8per cent cellulose and 8 per cent The following example illustrates theinvenalkali and having a salting point of 0.5 in a tion: precipitatingbath comprising 90 per cent metha- Viscose having a content of celluloseof 8 per n01 and 10 per cent of water, cutting the freshly cent and acontent of alkali of 8 per cent is coagulated xanthate threads intostaples and deripened to a salt point of 0.5 and then spun in acomposing said threads by means of a hot salt solution composed of percent of methanol and solution having a temperature of about 103.

10 per cent of Water. The freshly coagulated fibers are then cut intostaple lengths and de- AU ESSELMANlfI. composed by means of a hot saltsolution having FRITZ DAVIDSHOFER.

